Electric lifting jack



Oct. 22, 1940. R. 1'. WATTS ELECTRIC LIFTING JACK 4 Sheats-Sheet 1 INVENTOR. g; 7." h/ -ato Filed March 22, 1938 Filed March 22', 1938 4 Sheets-Sheet 3 INVENT OR. (W m:

ATTORNEY Oct. 22, 1940. R 1- WATTS 2,218,733

ELECTRIC LIFTING JACK File'd March 22, 1958 4 Sheets-Sheet 4 E n, HI HI Patented Oct. 22,

PATENT j OFFICE,

memo IJFTING .mox

Roy T. Watts, Miami Beach, Fla assignmto himself and Paul Ostruk Application March 22, 1938, Serial No. 197.333

6 Claims.

This invention relates to a jacking arrangement for automobiles or like vehicles, whereby a lifting jack chassis of said vehicle. In this is secured on the lower part of the particular invention two jacks are utilized, each one of which 7 said jack is to descend,

is mounted on either side of the car.

An object of this invention is to provide a jack that is simple and sturdy in construction which would not likely to become jammed, or otherwise tend to get out of order.

' A further object of this invention is to provide a jack arrangement .inwhich the movement thereof is attained'throughthe medium of an electric motor, said motor battery of .the" fear. 1 mounted on the body A further a switch on said jack for shutting to said motor when one of said of the jack.

being energized by the The motor aforesaid is object of this invention is to provide off the current jacks is either completely expanded or in completely retracted position.

andto cause rotation of the motor in the opposite direction when the jack is to ascend. Saidpolarity switch operates through the medium of the movement of-the jack itself, said operation being performed automatically. f

A furtherobject is to provide a manually operated switch on the switch panel of the car, said switch causing theoperation of either one of the.

- jacks.

,A further object is to have a switch mounted 85 on each one of the jacks and said operated by jacks. tingoif current operative jack when one of operating.

Referring to the drawings:

'Fig. 1 is a side view of sition of the jack switches being the functional movement of said Said switches serve the function of shutleading to the motor of the inthe jacks aforesaid is the car showing the powhen said jack is retracted.

The figure also shows the manually operated switch for operating the jacks.

Fig. 2 is'a partial sectional view of the jack, the

figure also shows motor gear box and nection with said motor. Said in an'expanded position.

Fig. 3 is a section on the line the location of the electric switches operating in conjack is shown I 3-3 of Fig. 2.

Fig.4 shows the relation of parts of the jack shown in Fig. 2 when said jack is in retracted position. The figure also the switch handles for operating s shows the position of a d. mo or.

to a small pinion gear rearof the jack I2. The gear Fig. 5 is a partial sectional view of Fig. 4 taken on a line 5-5 showing the relation of the electric motor and gears operating the jack.

Fig. 6 is a diagrammatic circuit with switches included therein, the setting of said switches being at the time when the jack is in a retracted position.

Fig. 6 shows a circuit and the setting of the switchesconnected therein being at the time when one of the jacks is starting to expand. 1

Fig. 6 showsa circuit and the setting of the switches connected therein when the other or' opposite side jack is starting to expand.

Referring to Fig. 1, the numeral I is the body of the car, H is the chassis of said car, I2 is the expanding jack, said' jack is shown in retracted position. I3 is a motor starting switch box having a button M for operating one jack, and a button l to operate the second jack- A wire l4 extending from the switch box l3 2 is connected to a motor 36 that is mounted on the gear box arrangement l6 the latter being mounted on the jack I2 (see Fig. 4). A wire l5 extending from the switch box I3 is connected to the opposite jack, not tending from switch box I3 is a part of the motor circuit as shown in Fig. 6 which will be described hereinafter.

Referring to Figs. 2, 3, 4, and 5, the jack |2 comprises a knee hinged unit having knee hinged U-shapedlink arms |8, I9, 26, 2|. The U-shaped link arms 3 and I9 are hinged respectively at 22 and 23 to a shoe 24 which is 'secured to the chassis ll of the car.

The opposite end of the arms l6 and I9 is hingingly connected to elongated blocks 25 and 26 through the medium of the hinge screws 21.

The U-shaped arms 2|] and 2| are likewise hingingly secured to the blocks 25 and 26, the other end thereof being hingingly secured at 28 and 29 to the shoe 30.

A screw shaft 3|, having a right hand thread 32 on one end and a left hand thread .33 on the other end thereof is threaded through the blocks 25 and 26. A gear box 34 which contains a gear 35 that 5 is pinned to the shaft 3| supports the electric motor 36. The electric motor 36 operates a small pinion gear 31 which in turn engages with a larger gear 38, said gear 38 integrally connected Both gears are pinned on a shaft 43 and rotating in bearings located in the gear box 34. The pinion gear 39 engages with and operates the gear 35. A floating plate 4| is located in the box 34 is secured shown. A wire H ex- 25 box l3 held on the dash to an extension member 42 of the floatihg'plate 4lby means of the screws 43.

The arms l8, I9, 20, 2| comprises two U-shaped sections.

A pair of switch boxes 44 and 45 are located on the gear box 34. The switch box 44 has an arm 46 which serves to shut off the current to the motor when the jack is fully expanded as shown in Fig. 2 and fully retracted as shown in Fig. 4. The switch arm 46 is operated by one of the sides of the U-shaped arm IS. A switch handle 41 is also operated by U-shaped arm 18' when the jack is in the position shown in Fig. 2. This handle operates a switch which changes the polarity of the electric-motor when the jack is in an expanded position.

Another switch handle 48 changes the polarity of the current leading to the motor when 'thejack is in a retracted position shown'in Fig. 4. And further, a handle 49 serves to shut off the-current to the motor of the opposite jack of one of the jacks that is operated. In other words the aforesaid described function will prevent the opera tion of both jacks simultaneously.

The switches which are located in the boxes 44 and 45 are diagrammatically shown in Figs.

6, 6 and 6 I p The operation Qf'thejack arrangement is 'as follows:

Referring to Fig. 1, jack I2 is shown in. retractive position. When the operator desires to operate the left or right sidejack, he presses button I4 or l5, depending on which jack isto be used. The aforesaid buttons are mounted upon a switch board of the automobile I 0.

When the button 14 is depressed as shown in Fig. 6 a circuit is then closed which permits current from the battery B to flow through the switch 45, which is mounted on'the opposite jack, then through the medium of the wiring l4 through the switch l3, wire ll, through the polarity switch 48, motor 36- and to ground. When this occurs, the motor armature rotates in a clockwise direction and as a result the jack I2 is caused to expand in the, mannershown in Fig. 2.

As soon as the jack starts expanding from the position in Fig. 4, the switch handle 49 is freed from its depressed and closed position shown in said figures. The switch 44 which is normally open when the jackis collapsed, (shown in Fig. 6), will close as shown in Fig. 6

The functions as above stated occur just the instant the jack l2 starts to expand, so that when the operator of the car removes the pressure from the knob l4 of switch l3, said switch returns to its original position, and the motor will continue to operate because of current flowing to it in the circuit comprising the battery B, switch 45 switch 44 throughthe polarity switch side 48 and the motor 36 to ground.

As soon as the jack shall have been completely expanded, the switch handle 46 will be again depressed and closed by the jack arm l8 and the switch 44 will thereupon open thus cutting off the flow of. current .to the motor 36. At the same time the switch handle 41 will be depressed, thus changing the polarity of current flowing through the motor.

When it is desired to return the jack to its collapsed position, the knob I4 is again depressed by the operator. Current from the battery B will then flow through the switch 45 through the wire 14 switch l3, wire l1, polarity switch side 41 and to ground. Since the polarity of the curshown in Fig.

rent flowing through the motor has been reversed. the motor. 38 will rotate in an anti-clockwise direction which will cause the jack to return to its original resting position.

An instant before the jack is entirely retracted the polarity switch handle 48 will be depressed thereby reversing the polarity of the motor, and also the switch handle 49 will be depressed and thereby closing the switch 45*. r

The left and right side jacks carry switches 45. These switches serve to disconnect the jack not selected for service from the battery as soon as the selected jack is switched in for service. Therefore should the left side jack be selected, the switch 45 that is mounted on said jack is opened so that the right jack cannot operate.

Fig. 6 illustrates the position of the switches when the right side jack is used. The operation of both jacks and their respective circuits are identical.

The wire connecting the motor 36 to the battery is not shown in Figs. 2, 3, 4 and 5.

The wiring consists of substantial flexible insulated wire secured to one of the arms of thejack and said wire flexing with said jack.

It is understood that each jack carries the same number of switches and switch arms as 2, and the operation of both jacks is identical.

The switch I3 is preferably designed to operate on the fulcrum arm principle so that only one side'of the switch can be operated. The switch aforesaid is restored to its resting position as shown.

The motor 36 through the medium of the gears inside the box 34 and the threaded shaft 3| causes said jack to expand or retract-dependingupon'the operation of the motor whether the armature of said motor rotates in a clockwise or anti-clockwise direction.

The shaft 3| has a right hand thread on side 32 of said shaft and a left hand thread on the side 33. The plate 4! supports the gear box 34 on the motor 38. Said motor moving along with themovement of the jacks when the jacks expand or -retract. v

While the invention has been described in detail with specific examples, such examples are illustrative and are not given as limitations, since other modifications within the spirit and scope of the invention will be apparent to those skilled in the art.

Hence, the invention is' to be understood as limited only as indicated in the appended claims in which the intent is to set forth all the novelty over the prior art.

I Now, having described my invention what I- larity depending upon the position of said jack.

a cut off switch operating in unison with said polarity switch for automatically cutting off the current: andswitch means in said set of switches for cutting off the current to one of the jacks of said jack arrangement when the opposite jack of said jack arrangement is in operation. 3

2. In a jack arrangement of, the class described including a pair of jacks secured to the chassis on either side of said car, a motor for operating each of said jacks included in said jack arrangement, switch means included in said automobile for operating either one of said jacks, an

automatic switch also included in each of said jacks for automatically'reversing the polarity of the flow of current into said motor when said jack is fully expanded or retracted, a motor .cut of! switch includedjn each jack arrangement, for operating simultaneously with said polarity reversing switch, and automatic switch means also included for rendering one of the jacks of said jack arrangement inoperative while the opposite side jack is in operation.

3. In a lifting jack arrangement for automotive vehicles, said arrangement including a pair of jacks mounted respectively oneach side of said vehicle, each of said pair of jacks including a pair of oppositely disposed knee hinged link arms, said link arms caused to expand or retract through the medium of electric motor means and gearing means operabiy connected therewith. said motor means included in a circuit, a power source in said circuit, said circuit also including current control switching means, said last means also mounted on each of said pair of link arms of said jacks, said switching means controlling current flow into said motor means; manually operated key circuit closing means in said vehicle I also included in said circuit, said key circuit closing means for selectively connecting current tothe motor means of whichever jackthatshall have been selected, and the jack not selected remaining disconnected and non-operative; and

pole changer switching means for reversing current flow in said motor means, said current control switching means and said pole changer switching means operating simultaneously consequent to the expanding or retracting operation of the link arms of the jack that shall have been selected by the key circuit closing means aforesaid.

4. The structure as set forth in claim 3, said key circuit closing means including a balanced bar member, cooperating contacts at each end thereof, said bar member causing the contacting of said cooperating contacts by the depression of either end thereof, and which end of said bar that is depressed being dependent upon whichever jack is to be selected for operation as. set forth.

'5. In a jack arrangement of said jacks in said switch having an arm operably in connection for automobiles or like vehicles including a pair of jacks each or said jacks having a pair of flexibly held knee hinged link arms, each of said pair of link arms connected to a shoe; a motor operating a gear train also included and connected with each pair of said link arms, said gear train engaging a threaded shaft, said shaft rotating in a pair of threaded bearings, said bearings mounted on said pair of link arms, said motor and gear train and said threaded shaft causing said link arms of said jacks to expand or retract depending upon the direction'of rotation of said motor; and switch means included-in said jack arrangement for controlling the operation of said motor, said switch means including a polarity changing switch and an arm in connection therewith for automatically reversing the polarity of the directionof flow of current into said motor when said jack is completely expanded or retracted; and a cut-ofi therewith, said cut-off switch for automatically cutting off the current, said polarity switch and said cut-off switch comprising said switch means operating approximately 'at the same time; and key push button means for selectively starting the motor of either one of said pair of jacks while the jack not selected remaining electrically disconnected and inoperative.

6. In a jack arrangement for automobiles'or like vehicles, said arrangement including a pair of jacks, each of said pair of jacks mounted respectively on each side of saidvehicle, each of said jacks including a pair of knee hinged link arms, said arms caused to expand or retract through the medium of an electric motor mounted on said link arms, a threaded shaft secured to said link arms, said shaft engageable with a gear train that is connected to the armature shaft of said motor; switch means included in said jack arrangement to cause the flow of current from a power source in said vehicle into the motor of one jack simultaneously with the disconnection of current flow to the opposite jack; and polarity reversing means in said vehicle for reversing the polarity of current flow from said power source into the motor mounted upon the jack that shall have been selected for operation whereby the rotation thereof may be reversed and thereby causing said link arms of said selected jack either to expand or retract, saidpolarity reversing means operable through the medium of the expansion or retracting movement of the jack aforesaid.

, ROY T. WATTS. 

